In the last decades, the epidemic spreading of eating disorders and obesity has raised the question whether certain highly palatable foods may be responsible for the development of a "food dependence". In fact, epidemic eating disorders and obesity, like drug addiction, can be conceptualized as chronic relapsing conditions with alternating periods of abstinence (e.g., dieting to avoid "forbidden" foods) and relapse (uncontrollable eating of palatable foods) that continue despite negative consequences. Eating disorders and obesity very frequently occur comorbidly with anxiety and mood disorders;however the neurobiological link between the two pathological conditions is poorly understood. We have recently proposed a new reliable animal model of palatable food dependence which contributes to the understanding of the etiology of compulsive eating and comorbid anxiety and affective disorders. Compulsive eating may be generated by the recruitment of the extrahypothalamic corticotropin-releasing factor (CRF) brain stress systems and by the emergence of a negative emotional state during abstinence, analogous to withdrawal from abused drugs. Therefore, relying on the general hypothesis that withdrawal generates palatable food overeating as a form of "self-medication," the proposed application will investigate the relationship between compulsive eating and comorbid anxiety and mood disorders. Specifically, the experiments of the proposed Specific Aims use a combined behavioral, pharmacological and molecular approach to elucidate: i) the brain sites important for the pharmacological effects of CRF1 receptor antagonists on the consummatory, emotional and motivational components of compulsive eating;ii) the effects of acute mild stress on food consumption, affectivity, and HPA and CRF responses, in animals with a history of palatable diet-cycling during protracted abstinence;iii) the role of the CRF/CRF1 system in the adaptations of the brain reward system and in the depressive-like behavior induced by the palatable diet alternation. This proposal will elucidate the neurobiological relationship between compulsive eating and comorbid anxiety and mood disorders through the lens of negative reinforcement. A better understanding of the etiology of compulsive eating would help prevent the onset of eating disorders and obesity, and would increase the potential for pharmacological intervention for tens of millions of people. PUBLIC HEALTH RELEVANCE: These experiments will provide critical information about the neurobiological substrates of compulsive eating of palatable food, and their relevance in the development of stress sensitivity and comorbid anxiety and mood disorders. Such information is important for understanding the etiology of eating disorders and obesity and for the development of more efficacious pharmacological treatments.